When a display device displays an image, pixel units need to be scanned using shift register, i.e., a gate driving circuit. The shift register includes a plurality of cascaded shift register units, and each shift register unit corresponds to one row of pixel units. The progressive scanning and driving on each row of pixel units in the display device is realized by the plurality of cascaded shift register units, for displaying an image.
A conventional shift register unit usually includes an input module, i.e., an input circuit, an output module, i.e., an output circuit, and a noise reduction module, i.e., a noise reduction circuit. The input module is for inputting an electric potential of an output terminal of an upper-one-stage shift register unit to a pull-up node, to pull up the electric potential of the pull-up node. The output module is for outputting a driving signal to an output terminal under the control of the pull-up node. The noise reduction module is for pulling down the electric potential of the pull-up node and the output terminal under the control of a clock signal, thereby realizing noise reduction at the pull-up node and the output terminal.
However, because the noise reduction module is controlled by the clock signal, when the clock signal is at a low level, transistors in the noise reduction module cannot be effectively turned on. Accordingly, noise exists at the pull-up node and the output terminal in the conventional shift register unit.